Levels like these take me back, and it's crazy to see how prevalent a lot of the fundamentals shown in Ebb still are today. I'm a big fan of how SirHadoken uses specific shapes within the structures in order to make them feel like they "fit together" nicely - particularly, around 0:25 where multiple layers are introduced. I like how the inner highlights of the rectangle-in-rectangle structures are hue shifted slightly to make them stand out more and create a more distinct set of layers within the blocks, and the black corner pieces used as an accent also accomplish the same goal quite well. I'm especially a fan of the "stacked" structures with multiple vertical layers, as the contrast between their base colours (including black and white) and the often complementary outline colour makes every detail stand out very nicely against the simple backgrounds.

The structuring also makes the gameplay very intuitive, a concept that even nowadays I still don't see done very often in easier levels. Black groundspikes are used to fill spaces between structures, but only when the player might expect a path to be where the groundspikes are, which does a good job making the intended path clearer while also filling some excess negative space. This is most prevalent around 0:53 with the more open, blocky structures in the UFO part, and particularly here it works well because of the high verticality of the part creating some ambiguity in regards to the intended path with traditional structuring. SirHadoken also uses some translucent bricks to "connect" many of the structures vertically, which grounds them to each other and makes the level as a whole feel more complete and reduces the feeling of structures "floating" in space with no attachment to anything else in the level. (edited)

Ebb isn't perfect; many of the colour choices are pretty jarring (especially the complementary ones) or washed out, the air decoration lacks much thought behind it and consists mostly of randomly placed saw decoration, and the structuring shape does get quite repetitive as it rarely changes throughout the level. However, given the limited editor tools available, and the general state of created levels around mid 2.0, Ebb is quite impressive and very ahead of its time, and demonstrates a good understanding of many design fundamentals that are still in use today.